diff --git a/.github/workflows/doc.yml b/.github/workflows/doc.yml
index e015f1e36..1341b8af1 100644
--- a/.github/workflows/doc.yml
+++ b/.github/workflows/doc.yml
@@ -7,7 +7,7 @@ jobs:
   all:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Generate doxygen
         uses: mattnotmitt/doxygen-action@v1
       - name: Deploy to github pages
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 70d4abad2..d82b3c9df 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -12,7 +12,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: make eigen
         run: make eigen
       - name: generate makefile
@@ -43,7 +43,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: Install python dependencies for simulation tests
         run: pip install -r requirements.txt
       - name: doctest for simulation test utils
@@ -65,7 +65,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: make eigen
         run: make eigen
       - name: generate makefile
@@ -87,7 +87,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: make eigen
         run: make eigen
       - name: generate makefile
@@ -109,7 +109,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - name: generate makefile
         run: make makefile-lib
       - name: generate message headers
diff --git a/.github/workflows/wasm.yml b/.github/workflows/wasm.yml
index e3384cab6..6a55eabc0 100644
--- a/.github/workflows/wasm.yml
+++ b/.github/workflows/wasm.yml
@@ -7,7 +7,7 @@ jobs:
       - name: work around permission issue
         run: git config --global --add safe.directory /__w/quisp/quisp
       - name: Check out repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           submodules: true
       - name: wasm build
@@ -27,7 +27,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.event_name == 'push' && (github.ref == 'refs/heads/master' || startsWith(github.ref, 'refs/tags/') || startsWith(github.ref, 'refs/heads/demo-')) }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           repository: 'sfc-aqua/quisp-online'
       - uses: actions/download-artifact@v4